package io;
import java.util.regex.*;
import java.io.*;
import java.util.*;
public class DirList3 {
    public static void main(final String[] args) {
        File path=new File(".");
        String[] list;
        if(args.length==0)
            list=path.list();
        else
            list=path.list(new FilenameFilter() {
                private Pattern pattern=Pattern.compile(args[0]);
                @Override
                public boolean accept(File dir, String name) {
                    return pattern.matcher(name).matches();
                }
            });
        Arrays.sort(list,String.CASE_INSENSITIVE_ORDER);
        for(String dirItem:list){
            System.out.println(dirItem);
        }
    }
}
